Re: [PATCH 07/15] usb: musb: Handle cable status better for 2430 glue layer

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [160511 17:56]:
> We may have drivers loaded but no configured gadgets and MUSB may be in
> host mode. If gadgets are configured during host mode, PM runtime will
> get confused.
...

> @@ -307,6 +350,9 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
>  		dev_dbg(dev, "ID float\n");
>  	}
>  
> +	if (!glue->cable_connected)
> +		omap2430_set_power(musb, glue->enabled, cable_connected);
> +

Oops sorry I messed up while cleaning up. This should be just cable_connected
here instead of glue->cable_connected. Otherwise we won't idle on cable
unplug as we're always using the cached value instead of the current
value.

Updated patch below.

Regards,

Tony

8< -----------------
From: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Date: Mon, 9 May 2016 07:50:57 -0700
Subject: [PATCH] usb: musb: Handle cable status better for 2430 glue layer

We may have drivers loaded but no configured gadgets and MUSB may be in
host mode. If gadgets are configured during host mode, PM runtime will
get confused.

Disable PM runtime from gadget state, and do it based on the cable
and last state.

Note that we may get multiple cable events, so we need to keep track
of the power state.

Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>

--- a/drivers/usb/musb/omap2430.c
+++ b/drivers/usb/musb/omap2430.c
@@ -49,6 +49,9 @@ struct omap2430_glue {
 	enum musb_vbus_id_status status;
 	struct work_struct	omap_musb_mailbox_work;
 	struct device		*control_otghs;
+	bool			cable_connected;
+	bool			enabled;
+	bool			powered;
 };
 #define glue_to_musb(g)		platform_get_drvdata(g->musb)
 
@@ -234,6 +237,45 @@ static inline void omap2430_low_level_init(struct musb *musb)
 	musb_writel(musb->mregs, OTG_FORCESTDBY, l);
 }
 
+/*
+ * We can get multiple cable events so we need to keep track
+ * of the power state. Only keep power enabled if USB cable is
+ * connected and a gadget is started.
+ */
+static void omap2430_set_power(struct musb *musb, bool enabled, bool cable)
+{
+	struct device *dev = musb->controller;
+	struct omap2430_glue *glue = dev_get_drvdata(dev->parent);
+	bool power_up;
+	int res;
+
+	if (glue->enabled != enabled)
+		glue->enabled = enabled;
+
+	if (glue->cable_connected != cable)
+		glue->cable_connected = cable;
+
+	power_up = glue->enabled && glue->cable_connected;
+	if (power_up == glue->powered) {
+		dev_warn(musb->controller, "power state already %i\n",
+			 power_up);
+		return;
+	}
+
+	glue->powered = power_up;
+
+	if (power_up) {
+		res = pm_runtime_get_sync(musb->controller);
+		if (res < 0) {
+			dev_err(musb->controller, "could not enable: %i", res);
+			glue->powered = false;
+		}
+	} else {
+		pm_runtime_mark_last_busy(musb->controller);
+		pm_runtime_put_autosuspend(musb->controller);
+	}
+}
+
 static void omap2430_musb_mailbox(enum musb_vbus_id_status status)
 {
 	struct omap2430_glue	*glue = _glue;
@@ -259,6 +301,13 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
 	struct musb_hdrc_platform_data *pdata = dev_get_platdata(dev);
 	struct omap_musb_board_data *data = pdata->board_data;
 	struct usb_otg *otg = musb->xceiv->otg;
+	bool cable_connected;
+
+	cable_connected = ((glue->status == MUSB_ID_GROUND) ||
+			   (glue->status == MUSB_VBUS_VALID));
+
+	if (cable_connected)
+		omap2430_set_power(musb, glue->enabled, cable_connected);
 
 	switch (glue->status) {
 	case MUSB_ID_GROUND:
@@ -268,7 +317,6 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
 		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
 		musb->xceiv->last_event = USB_EVENT_ID;
 		if (musb->gadget_driver) {
-			pm_runtime_get_sync(dev);
 			omap_control_usb_set_mode(glue->control_otghs,
 				USB_MODE_HOST);
 			omap2430_musb_set_vbus(musb, 1);
@@ -281,8 +329,6 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
 		otg->default_a = false;
 		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
 		musb->xceiv->last_event = USB_EVENT_VBUS;
-		if (musb->gadget_driver)
-			pm_runtime_get_sync(dev);
 		omap_control_usb_set_mode(glue->control_otghs, USB_MODE_DEVICE);
 		break;
 
@@ -291,11 +337,8 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
 		dev_dbg(dev, "VBUS Disconnect\n");
 
 		musb->xceiv->last_event = USB_EVENT_NONE;
-		if (musb->gadget_driver) {
+		if (musb->gadget_driver)
 			omap2430_musb_set_vbus(musb, 0);
-			pm_runtime_mark_last_busy(dev);
-			pm_runtime_put_autosuspend(dev);
-		}
 
 		if (data->interface_type == MUSB_INTERFACE_UTMI)
 			otg_set_vbus(musb->xceiv->otg, 0);
@@ -307,6 +350,9 @@ static void omap_musb_set_mailbox(struct omap2430_glue *glue)
 		dev_dbg(dev, "ID float\n");
 	}
 
+	if (!cable_connected)
+		omap2430_set_power(musb, glue->enabled, cable_connected);
+
 	atomic_notifier_call_chain(&musb->xceiv->notifier,
 			musb->xceiv->last_event, NULL);
 }
@@ -443,6 +489,8 @@ static void omap2430_musb_enable(struct musb *musb)
 	struct musb_hdrc_platform_data *pdata = dev_get_platdata(dev);
 	struct omap_musb_board_data *data = pdata->board_data;
 
+	omap2430_set_power(musb, true, glue->cable_connected);
+
 	switch (glue->status) {
 
 	case MUSB_ID_GROUND:
@@ -481,6 +529,8 @@ static void omap2430_musb_disable(struct musb *musb)
 	if (glue->status != MUSB_UNKNOWN)
 		omap_control_usb_set_mode(glue->control_otghs,
 			USB_MODE_DISCONNECT);
+
+	omap2430_set_power(musb, false, glue->cable_connected);
 }
 
 static int omap2430_musb_exit(struct musb *musb)
@@ -653,11 +703,13 @@ err0:
 
 static int omap2430_remove(struct platform_device *pdev)
 {
-	struct omap2430_glue		*glue = platform_get_drvdata(pdev);
+	struct omap2430_glue *glue = platform_get_drvdata(pdev);
+	struct musb *musb = glue_to_musb(glue);
 
 	pm_runtime_get_sync(glue->dev);
 	cancel_work_sync(&glue->omap_musb_mailbox_work);
 	platform_device_unregister(glue->musb);
+	omap2430_set_power(musb, false, false);
 	pm_runtime_put_sync(glue->dev);
 	pm_runtime_disable(glue->dev);
 
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